78. And strive hard in Allah’s Cause as you ought to strive (with sincerity and with all your efforts). He has chosen you (to convey His Message, Islam), and has not laid upon you in religion any hardship, it is the religion of your father Ibrahim. It is He (Allah) Who has named you Muslims both before and in this (the Qur’an), that the Messenger may be a witness over you and you be witnesses over mankind! So perform As-Salat, give Zakat and hold fast to Allah [i.e. have confidence in Allah, and depend upon Him in all your affairs] He is your Maula (Patron, Lord, etc.), what an Excellent Maula and what an Excellent Helper!

Tafsir Ibn Kathir Volume 6, Page 622.

And strive hard in Allah’s cause as you ought to strive means, with your wealth and your tongues and your bodies. This is like the Ayah:

﴿اتَّقُواْ اللَّهَ حَقَّ تُقَاتِهِ﴾

(Have Taqwa of Allah as is His due.) 3:102

﴿هُوَ اجْتَبَـكُمْ﴾

(He has chosen you,) means, `O Ummah of Islam, Allah has selected you and chosen you over all other nations, and has favored you and blessed you and honored you with the noblest of Messengers and the noblest of Laws.’

﴿وَمَا جَعَلَ عَلَيْكمْ فِى الدِّينِ مِنْ حَرَجٍ﴾

(and has not laid upon you in religion any hardship) He has not given you more than you can bear and He has not obliged you to do anything that will cause you difficulty except that He has created for you a way out. So the Salah, which is the most important pillar of Islam after the two testimonies of faith, is obligatory, four Rak`ahs when one is settled, which are shortened to two Rak`ah when one is traveling. According to some Imams, only one Rak`ahs is obligatory at times of fear, as was recorded in the Hadith. A person may pray while walking or riding, facing the Qiblah or otherwise. When praying optional prayers while traveling, one may face the Qiblah or not. A person is not obliged to stand during the prayer if he is sick; the sick person may pray sitting down, and if he is not able to do that then he may pray lying on his side. And there are other exemptions and dispensations which may apply to the obligatory prayers and other duties. So the Prophet said:

«بُعِثْتُ بِالْحَنِيفِيَّةِ السَّمْحَة»

(I have been sent with the easy Hanifi way.) And he said to Mu`adh and Abu Musa, when he sent them as governors to Yemen:

«بَشِّرَا وَلَا تُنَفِّرا وَيَسِّرَا وَلَا تُعَسِّرَا»

(Give good news and do not repel them. Make things easy for the people and do not make the things difficult for them.) And there are many similar Hadiths. Ibn `Abbas said concerning the Ayah,

﴿وَمَا جَعَلَ عَلَيْكمْ فِى الدِّينِ مِنْ حَرَجٍ﴾

(and has not laid upon you in religion any hardship), “This means difficulty.”

﴿مِّلَّةَ أَبِيكُمْ إِبْرَهِيمَ﴾

(It is the religion of your father Ibrahim. ) Ibn Jarir said, “This refers back to the Ayah,

﴿وَمَا جَعَلَ عَلَيْكمْ فِى الدِّينِ مِنْ حَرَجٍ﴾

(and has not laid upon you in religion any hardship) meaning, any difficulty.” On the contrary, He has made it easy for you, like the religion of your father Ibrahim.